Die device

ABSTRACT

There is provided a die device capable of reliably releasing a workpiece from a die even when the workpiece has an undercut, and conveying the workpiece to a next process. A die device including: a lower die; and a lifter that lifts a pressed workpiece from the lower die, the lower die having an undercut region which is a portion that interferes with the workpiece when the workpiece is moved along a press direction, the lifter including: a vacuum cup that comes into contact with the workpiece; a rod part having a distal end provided with the vacuum cup; and a linear drive servomotor for causing the rod part to advance/retreat in an axial direction, and further including a rotary drive servomotor that turns the lifter in a direction orthogonal to the axial direction, wherein the lifter moves the workpiece by combining both movement along the press direction and movement in a direction inclined to the press direction.

This application is based on and claims the benefit of priority fromJapanese Patent Application No. 2020-058115, filed on 27 Mar. 2020, thecontent of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates to a die device.

Related Art

When a pressed product is formed, a workpiece is formed by using amovable punch from the direction intersecting with the mold clampingdirection using a cam driver or the like, so that the workpiece isformed in an undercut shape with respect to the die clamping direction.At that time, a movable die for forming an undercut portion isretreated, and the workpiece is released from a lower die (for example,Japanese Unexamined Patent Application, Publication No. 2013-078777).

Generally, in a case where an automobile body part is formed by pressforming, the automobile body part is formed through a plurality ofprocesses such as draw forming, trim forming, bend forming, and piercingforming. In this case, a plurality of dies are required, and thereforeit is conceivable to integrate the processes and reduce the installationarea of the equipment, and integrate the plurality of dies to perform,for example, draw forming, bend forming, and trim forming, by one die.In such a die, it is not possible to provide a space in a lower die forsufficiently retreating a movable die (movable die) that avoids anundercut, and there is a possibility that the workpiece cannot bereleased from a die.

Patent Document 1: Japanese Unexamined Patent Application, PublicationNo. 2013-078777

SUMMARY OF THE INVENTION

An object of the present invention is to provide a die device capable ofreliably releasing a workpiece from a die even when the workpiece has anundercut, and conveying the workpiece to a next process.

The present invention solves the aforementioned problem by the followingsolutions. In order to facilitate understanding, description will bemade with reference numerals corresponding to embodiments of the presentinvention, but the description is not limited to the embodiments.

A first aspect of the invention relates to a die device (1) including:

-   -   a lower die (10); and    -   a lifter (20, 20B) that lifts a pressed workpiece (W) from the        lower die (10), the lower die (10) having an undercut region        which is a portion that interferes with the workpiece (W) when        the workpiece is moved along a press direction, the lifter (20,        20B) including: an abutting part (27, 206) that comes into        contact with the workpiece (W); a rod part (23 a, 204 a) having        a distal end provided with the abutting part (27, 206); and a        driving means (24, 205) for causing the rod part (23 a, 204 a)        to advance/retreat in an axial direction, the die device further        including a turning drive part (25, 201 a, 202 a) that turns the        lifter (20, 20B) in a direction orthogonal to the axial        direction, wherein the lifter (20, 20B) moves the workpiece (W)        by combining both movement along the press direction and        movement in a direction inclined to the press direction.

According to a second aspect of the invention, in the die device (1)described in the first invention, the undercut region of the lower die(10) includes:

a movable die part (12) that moves in such a direction as to release anundercut; and a fixed die part (11) having a portion that remains as anundercut in relation with the workpiece (W) even in a state in which themovable die part (12) moves to perform release.

According to a third aspect of the invention, in the die device (1)described in the first invention or the second invention, the abuttingpart (27, 206) is provided with a vacuum cup (27, 206).

According to a fourth aspect of the invention, the die device (1)described in any of the first invention to the third invention furtherincludes support lifters (30) that advance and retreat in a directionalong the press direction,

wherein the support lifters (30) are provided in at least each one of aturning direction and a counter-turning direction of the lifter (20,20B) with the lifter (20, 20B) interposed therebetween, the die device(1) including a control device (40) that controls protrusion positionsof the support lifters (30) in accordance with turning operation of thelifter (20, 20B).

According to a fifth aspect of the invention, in the die device (1)described in the fourth invention, the support lifters (30) are eachprovided with a sliding member (33) for enhancing sliding performancebetween the workpiece (W) and the support lifter, at a portion thatcomes into contact with the workpiece (W).

According to the present invention, it is possible to provide a diedevice capable of reliably releasing a workpiece even when the workpiecehas an undercut, and transporting the workpiece to a next process.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram illustrating a first embodiment of a die device 1according to the present invention;

FIG. 2 is a perspective view of a lifter 20;

FIG. 3 is a perspective view of a support lifter 30;

FIG. 4 is a block diagram illustrating an outline of a control block ofthe die device 1;

FIG. 5 is a sectional view of a lower die 10 and a workpiece W cut atthe position of the arrows A-A in FIG. 1;

FIG. 6 is a diagram illustrating a state in which a movable die part 12moves in such a direction as to release an undercut;

FIG. 7 is a diagram illustrating a state in which the workpiece W ismoved upward in the press direction;

FIG. 8 is a diagram illustrating a state in which the workpiece W isturned;

FIG. 9 illustrates a state in which the workpiece W is raised in theoblique direction from a position where the workpiece W is turned;

FIG. 10 is a perspective view illustrating a lifter 20B of a secondembodiment;

FIG. 11 is a sectional view illustrating the lifter 20B of the secondembodiment; and

FIGS. 12A to 12F are diagrams illustrating operation processes of thelifter 20B, the operation processes being arranged in order.

DETAILED DESCRIPTION OF THE INVENTION

Hereinafter, the best mode for carrying out the present invention willbe described with reference to the drawings and the like.

First Embodiment

FIG. 1 is a diagram illustrating a first embodiment of a die device 1according to the present invention. Each figure illustrated belowincluding FIG. 1 is a diagram schematically illustrated, and the sizeand the shape of each part are illustrated by being appropriatelyexaggerated or omitted in order to facilitate understanding. In thefollowing description, specific numerical values, shapes, materials andthe like will be described, but these can be appropriately changed.

The die device 1 of the first embodiment includes a lower die 10 and anupper die (not illustrated), and is used for press forming of a vehicleouter plate. In this embodiment, the die device used for press formingof the vehicle outer panel is described as an example. However, aworkpiece to be press-formed may be of other application. The lower die10 is provided with a male die part 11 of the vehicle outer plate thatconstitutes the vicinity of a central portion of a side surface of avehicle. Further, lifters 20 and support lifters 30 are disposed in themale die part 11.

The lifters 20 lift the pressed workpiece W from the lower die. Thelifters 20 of this embodiment are disposed at two locations, a B-pillarportion located at a central portion of a vehicle body and a rear fenderportion. In this embodiment, the lifters 20 disposed at theaforementioned two locations are disposed at positions where the centerof gravity of the workpiece W is interpose, and therefore the workpieceW can be raised in a well-balanced manner when the workpiece W israised.

FIG. 2 is a perspective view of each lifter 20. The lifter 20 includes abase part 21, a support member 22, a cylinder body 23, a linear driveservomotor 24, a rotary drive servomotor 25, a speed reducer 26, and avacuum cup 27.

The base part 21 is attached to the lower die 10, or a bolster or thelike that supports the lower die 10, and is fixed so as not to moverelative to the lower die 10.

The support member 22 is attached so as to be turnable (swingable) withrespect to the base part 21. The cylinder body 23 is fixed to thesupport member 22, and a rod part 23 a that advances and retreats fromthe cylinder body 23 movably penetrates the support member 22.

An upper portion of the cylinder body 23 is fixed to the support member22, and the cylinder body 23 can turn (swing) with respect to the basepart 21 together with the support member 22. The rod part 23 a advancesand retreats upward from the cylinder body 23.

The linear drive servomotor 24 is attached to the cylinder body 23, andis a driving means for causing the rod part 23 a to advance and retreatin the axial direction under control of a control device 40 describedlater.

The rotary drive servomotor 25 is fixed to the base part 21 via thespeed reducer 26. An output shaft (not illustrated) of the rotary driveservomotor 25 is connected to the support member 22 via an input shaftand an output shaft (both not illustrated) of the speed reducer 26.Consequently, the rotary drive servomotor 25 functions as a turningdrive part that is controlled by the control device 40 described laterto turn (swing) the support member 22 and the cylinder body 23 withrespect to the base part 21. This turning (swing) direction is thedirection orthogonal to the axial direction of the rod part 23 a.

The speed reducer 26 reduces rotational driving force of the rotarydrive servomotor 25 to transmit driving force for rotationally drivingthe support member 22.

The vacuum cup 27 is attached to a tip of the rod part 23 a, and has afunction as an abutting part that abuts on the workpiece W. The vacuumcup 27 is formed in a suction cup shape by an elastic body such aselastomer. Further, the vacuum cup 27 has a pipe (not illustrated)connected to a pressure regulator (not illustrated), and isdepressurized to suck and hold the workpiece W. The abutting part of thelifter 20 is not limited to the vacuum cup, and other means such asmagnetic force may be used.

With the above configuration, the lifters 20 can hold and lift (lift up)the workpiece W in accordance with the control of the control device 40,and further turn (swing) the held workpiece W.

Returning to FIG. 1, a plurality of the support lifters 30 are disposedin a region where the lifters 20 are not provided, and in the exampleillustrated in FIG. 1, the support lifters 30 are disposed at sixlocations. There is a risk that the workpiece W may vibrate to causeunstable behavior with just the lifters 20, and therefore the supportlifters 30 cooperate with the lifters 20 to support the workpiece W frombelow. It is desirable that the support lifters 30 are provided in atleast each one of the turning direction and the counter-turningdirection of each lifter 20 with the lifter 20 interposed therebetween,in order to suppress unstable behavior of the workpiece W. The number ofthe support lifters 30 and the arrangement of the support lifters 30 canbe appropriately changed according to a specific configuration of theworkpiece W.

FIG. 3 is a perspective view of each support lifter 30. The supportlifter 30 includes a cylinder body 31, a linear drive servomotor 32, anda sliding member 33. The support lifter 30 does not perform rotationaloperation like each lifter 20.

The cylinder body 31 is attached to the lower die 10, or the bolster orthe like that supports the lower die 10, and is fixed so as not to moverelative to the lower die 10.

The linear drive servomotor 32 is attached to the cylinder body 31, andis controlled by the control device 40 described later to cause a rodpart 31 a to advance and retreat.

The sliding member 33 is attached to a tip of the rod part 31 a, andsupports the workpiece without holding the workpiece W such that theworkpiece can slide and move freely on the sliding member 33. Thesliding member 33 can be made of, for example, urethane resin or thelike.

FIG. 4 is a block diagram illustrating an outline of a control block ofthe die device 1. The control device 40 is connected to the lifters 20and the support lifters 30. The control device 40 controls the drive ofthe lifters 20 by controlling the linear drive servomotors 24 of thelifters 20, the rotary drive servomotors 25, and vacuum pressuregenerating devices (not illustrated) connected to the vacuum cups 27.Further, the control device 40 controls the drive of the linear driveservomotors 32 of the support lifters 30.

FIG. 5 is a sectional view of the lower die 10 and the workpiece W cutat the position of the arrows A-A in FIG. 1. The arrow direction in FIG.5 indicates the press direction. As illustrated in FIG. 5, the lower die10 of this embodiment has an undercut region which is a portion thatinterferes with the workpiece when the workpiece W is moved along thepress direction. The lower die 10 includes a movable die part 12 thatmoves in such a direction so as to release this undercut.

FIG. 6 is a diagram illustrating a state in which the movable die part12 is moved in such a direction as to release the undercut. The movabledie part 12 moves in the direction of the arrow in FIG. 6, so that a gapS can be provided between the movable die part 12 and the workpiece W,and the workpiece W can be moved upward in the press direction. FIG. 7is a diagram illustrating a state in which the workpiece W is movedupward in the press direction. In order to move the workpiece W upwardin the press direction, the lifters 20 and the support lifters 30 arecontrolled by the control device 40 to raise the workpiece W. Themovable die part 12 retreats, so that the workpiece W can be movedupward in the press direction. However, when the workpiece W is raisedin the press direction as it is, the workpiece W cannot be completelyremoved from the lower die 10 because a portion that remains as anundercut exists between the male die part 11 and the workpiece W.

Therefore, the control device 40 causes the lifters 20 to turn (swing)the workpiece W. At this time, the control device 40 also appropriatelyadjusts the heights of the support lifters 30, so that the workpiece Wcan slide and move on the sliding members 33 of the support lifters 30.

FIG. 8 is a diagram illustrating a state in which the workpiece W isturned. The alternate long and short dash line in FIG. 8 indicates aposition where the workpiece W is present in the state of FIG. 7. Theworkpiece W is turned in the direction of the arrow in FIG. 8, so thatthe amount of interference at the undercut portion of the workpiece W isreduced.

Then, the control device 40 further extends the rod parts 23 a of thelifters 20 from a position where the workpiece W is turned, and raisesthe workpiece W in the oblique direction at an angle with respect to thepress direction.

FIG. 9 illustrates a state in which the workpiece W is raised in theoblique direction from the position where the workpiece W is turned. Thealternate long and short dash line in FIG. 9 indicates a position wherethe workpiece W is present in the state of FIG. 8. The workpiece W israised in the oblique direction from a position where the workpiece W isturned, so that the workpiece W can be completely released from thelower die 10 while avoiding interference due to the undercut. Afterthat, the control device 40 causes the lifters 20 to rotate (swing) theworkpiece W in the opposite direction, and further raise the workpiece Wwhile returning the advancing/retreating direction of the rod part 23 ato the press direction, so that the operation for releasing theworkpiece W is terminated.

As described above, according to the first embodiment, the turnablelifters 20 are provided, and therefore the workpiece W can beappropriately released from the die even in a case where the undercutremains. Further, according to the configuration of this embodiment, theamount of retreat of the movable die can be reduced, and therefore aplurality of dies can be integrated to realize efficient forming.

Second Embodiment

FIG. 10 is a perspective view illustrating a lifter 20B of a secondembodiment.

FIG. 11 is a sectional view illustrating the lifter 20B of the secondembodiment. The second embodiment is different from the first embodimentonly in that the lifters 20 in the first embodiment are replaced withthe lifters 20B. Therefore, herein, only each lifter 20B will bedescribed, and the same components as those in the first embodiment aredenoted by the same reference numerals as those in the first embodiment,and detailed description thereof will be omitted. The lifter 20B of thesecond embodiment includes cam members 201, a support member 202, acentral shaft 203, a cylinder body 204, a linear drive servomotor 205,and a vacuum cup 206.

The cam members 201 are attached to a lower die 10, or a bolster or thelike that supports the lower die 10, and is fixed so as not to moverelative to the lower die 10. Two cam members 201 are disposed so as toface each other. Further, the cam members 201 each have a cam groove 201a.

The support member 202 is fixed to a rod part 204 a, described later,and can move integrally with the rod part 204 a. Further, the supportmember 202 has pins 202 a. These pins 202 a are inserted into the camgrooves 201 a, and function as turning drive parts that move along thecam grooves 201 a by advancing and retreating movement of the rod part204 a to turn the lifters 20B. The support member 202 has through holes202 b, and the central shaft 203 described later penetrates the throughholes 202 b. The through holes 202 b are opened sufficiently large suchthat the through holes 202 b and the central shaft 203 do not come intocontact with each other.

The central shaft 203 is fixed to the cylinder body 204, and is insertedinto the cam members 201 in a rotatable state. Therefore, the cylinderbody 204 described later can turn (swing) with respect to the cammembers 201 about the central shaft 203.

As described above, the cylinder body 204 is attached to the cam members201 so as to be tunable (swingable) about the central shaft 203. The rodpart 204 a advances and retreats upward from the cylinder body 204.

The linear drive servomotor 205 is attached to the cylinder body 204,and is controlled by the control device 40 to cause the rod part 204 ato advance and retreat.

The vacuum cup 206 is attached to a tip of the rod part 204 a. Aspecific configuration of the vacuum cup 206 of the second embodiment isthe same as that of the vacuum cup 27 of the first embodiment.

FIGS. 12A to 12F are diagrams illustrating operation processes of thelifter 20B, the operation processes being arranged in order. The releaseoperation of the workpiece W by the lifter 20B starts from the stateillustrated in FIG. 12A, and is performed in the order of FIGS. 12B,12C, . . . 12F. As illustrated in FIG. 12, as the rod part 204 a extendsfrom a state in which the protrusion amount of the rod part 204 a is theshortest (FIG. 12A), the pins 202 a move along the cam grooves 201 a,and the cylinder body 204 and the rod part 204 a gradually are inclined.Then, in the latter half, the rod part 204 a further extends whilereturning the inclination of the cylinder body 204 and the rod part 204a, and operation for releasing the workpiece W is terminated (FIG. 12F).

As described above, according to the second embodiment, the sameoperation as that of the first embodiment can be performed without usinganother actuator such as the rotary drive servomotor 25 in the firstembodiment. In the second embodiment, the linear drive servomotor isdescribed as an example. However, a hydraulic drive cylinder such as anair cylinder may be used.

EXPLANATION OF REFERENCE NUMERALS

-   1 die device-   10 lower die-   11 male die part (fixed die part)-   12 movable die part-   20 lifter-   20B lifter-   21 base part-   22 support member-   23 cylinder body-   23 a rod part-   24 linear drive servomotor-   25 rotary drive servomotor-   26 speed reducer-   27 vacuum cup (abutting part)-   30 support lifter-   31 cylinder body-   31 a rod part-   32 linear drive servomotor-   33 sliding member-   40 control device-   201 cam member-   201 a cam groove-   202 support member-   202 a pin-   202 b through hole-   203 central shaft-   204 cylinder body-   204 a rod part-   205 linear drive servomotor-   206 vacuum cup (abutting part)-   W workpiece

What is claimed is:
 1. A die device comprising: a lower die; and alifter that lifts a pressed workpiece from the lower die, the lower diehaving an undercut region which is a portion that interferes with theworkpiece when the workpiece is moved along a press direction, thelifter comprising: an abutting part that comes into contact with theworkpiece; a rod part having a distal end provided with the abuttingpart; and a driving means for causing the rod part to advance/retreat inan axial direction, and the die device further comprising a turningdrive part that turns the lifter in a direction orthogonal to the axialdirection, wherein the lifter moves the workpiece by combining bothmovement along the press direction and movement in a direction inclinedto the press direction.
 2. The die device according to claim 1, whereinthe undercut region of the lower die includes: a movable die part thatmoves in such a direction as to release an undercut; and a fixed diepart having a portion that remains as an undercut in relation with theworkpiece even in a state in which the movable die part moves to performrelease.
 3. The die device according to claim 1, wherein the abuttingpart is provided with a vacuum cup.
 4. The die device according to claim1, further comprising support lifters that advance and retreat in adirection along the press direction, wherein the support lifters areprovided in at least each one of a turning direction and acounter-turning direction of the lifter with the lifter interposedtherebetween, the die device comprising a control device that controlsprotrusion positions of the support lifters in accordance with turningoperation of the lifter.
 5. The die device according to claim 4, whereinthe support lifters are each provided with a sliding member forenhancing sliding performance between the workpiece and the supportlifter, at a portion that comes into contact with the workpiece.
 6. Thedie device according to claim 1, wherein the undercut region of thelower die includes: a movable die part that moves in such a direction asto release an undercut; and a fixed die part having a portion thatremains as an undercut in relation with the workpiece even in a state inwhich the movable die part moves to perform release, and the abuttingpart is provided with a vacuum cup.
 7. The die device according to claim1, wherein the undercut region of the lower die includes: a movable diepart that moves in such a direction as to release an undercut; and afixed die part having a portion that remains as an undercut in relationwith the workpiece even in a state in which the movable die part movesto perform release, the die device further comprising support liftersthat advance and retreat in a direction along the press direction,wherein the support lifters are provided in at least each one of aturning direction and a counter-turning direction of the lifter with thelifter interposed therebetween, the die device comprising a controldevice that controls protrusion positions of the support lifters inaccordance with turning operation of the lifter.
 8. The die deviceaccording to claim 1, wherein the undercut region of the lower dieincludes: a movable die part that moves in such a direction as torelease an undercut; and a fixed die part having a portion that remainsas an undercut in relation with the workpiece even in a state in whichthe movable die part moves to perform release, the abutting part isprovided with a vacuum cup, the die device further comprising supportlifters that advance and retreat in a direction along the pressdirection, wherein the support lifters are provided in at least each oneof a turning direction and a counter-turning direction of the lifterwith the lifter interposed therebetween, the die device comprising acontrol device that controls protrusion positions of the support liftersin accordance with turning operation of the lifter.
 9. The die deviceaccording to claim 1, wherein the undercut region of the lower dieincludes: a movable die part that moves in such a direction as torelease an undercut; and a fixed die part having a portion that remainsas an undercut in relation with the workpiece even in a state in whichthe movable die part moves to perform release, the die device furthercomprising support lifters that advance and retreat in a direction alongthe press direction, wherein the support lifters are provided in atleast each one of a turning direction and a counter-turning direction ofthe lifter with the lifter interposed therebetween, the die devicecomprising a control device that controls protrusion positions of thesupport lifters in accordance with turning operation of the lifter,wherein the support lifters are each provided with a sliding member forenhancing sliding performance between the workpiece and the supportlifter, at a portion that comes into contact with the workpiece.
 10. Thedie device according to claim 1, wherein the undercut region of thelower die includes: a movable die part that moves in such a direction asto release an undercut; and a fixed die part having a portion thatremains as an undercut in relation with the workpiece even in a state inwhich the movable die part moves to perform release, the abutting partis provided with a vacuum cup, the die device further comprising supportlifters that advance and retreat in a direction along the pressdirection, wherein the support lifters are provided in at least each oneof a turning direction and a counter-turning direction of the lifterwith the lifter interposed therebetween, the die device comprising acontrol device that controls protrusion positions of the support liftersin accordance with turning operation of the lifter, wherein the supportlifters are each provided with a sliding member for enhancing slidingperformance between the workpiece and the support lifter, at a portionthat comes into contact with the workpiece.